package main

import "fmt"

func getFaceArea(radius float32) (area float32) {
	area = 3.14 * radius * radius
	return
}

func main() {
	demo51()
}

func demo51() {
	fmt.Println("请输入脸的半径：")
	var radius float32
	fmt.Scanf("%f", radius)
	area := getFaceArea(radius)
	fmt.Printf("面积为：%f", area)
}

func demo52() {
	fmt.Println("请输入脸的半径：")
	var radius float32
	fmt.Scanf("%f", radius)
	area := getFaceArea(radius)
	fmt.Printf("面积为：%f", area)
}
